Effect of TeO2 addition on the dielectric properties of CaCu3Ti4O12 ceramics derived from the oxalate precursor route

TL;DR

This study investigates how adding TeO2 to CaCu3Ti4O12 ceramics affects their dielectric properties, aiming to reduce dielectric loss while maintaining high permittivity for capacitor applications.

Contribution

It demonstrates that 2 wt% TeO2 addition significantly improves dielectric properties of CCTO ceramics derived from oxalate precursors.

Findings

Permittivity reached 7387 at 10 kHz with TeO2 addition.

Dielectric loss was reduced to 0.037 at 10 kHz.

Microstructural changes correlated with improved dielectric performance.

Abstract

CaCu3Ti4O12 (CCTO) ceramics which has perovskite structure gained considerable attention due to its giant permittivity. But, it has high tan {\delta} (0.1 at 1kHz) at room temperature, which needs to be minimised to the level of practical applications. Hence, TeO2 which is a good glass former has been deliberately added to CCTO nano ceramic (derived from the oxalate precursor route) to explore the possibility of reducing the dielectric loss while maintaining the high permittivity. The structural, morphological and dielectric properties of the pure CCTO and TeO2 added ceramics were studied using X-ray diffraction, Scanning Electron Microscope along with Energy Dispersive X-ray Analysis (EDX), spectroscopy and Impedance analyzer. For the 2.0 wt % TeO2 added ceramics, there is a remarkable difference in the microstructural features as compared to that of pure CCTO ceramics. This sample exhibited permittivity values as high as 7387 @ 10 KHz and low dielectric loss value of 0.037 @ 10 kHz, which can be exploited for the high frequency capacitors application.